The problem of detecting the presence of smoke and fire and carbon monoxide, hydrogen and hydrocarbon gases and vapors is associated with the problem of protecting life and property. Hazardous, potentially hazardous, or abnormal condition related to fires or explosions include the presence of certain toxic, combustible or detonatable gases and vapors such as carbon monoxide, hydrogen and gases and vapors of hydrocarbons such as methane and propane. The volatiles of most paints and varnishes, including the volatiles of numerous household and industrial compounds containing hydrocarbons are also associated with fire explosion and health hazards. Certain devices and systems currently do provide some capability for protecting life and property against the hazards of fires and toxic and combustible and detonatible gases and vapors. Sensor devices used in prior art systems include ionization and photoelectric chambers, for smoke detection, the heated, doped, semiconductors that work on the principle of resistance changes for adsorbtion of certain gases for detection of such gases, and thermostatic switches for detecting heat. All currently available systems using such devices exhibit shortcomings that fall short of total protection against the hazardous presences previously described. Deficiencies of some or all of the current systems include cost of installation, cost of maintenance, fluctuations in performance with unacceptable false alarm rates accompanying increasing sensitivity performance and failure to detect a fire that gives off low quantities of carbon monoxide. Significantly, the notification devices in prior art systems may create further danger to life and property through combustion or detonation of certain gases or vapors upon actuation of the sounding device itself. Additionally, most systems fail to provide a second power source for back-up emergency operation. Finally, most prior art devices require that the alarm circuitry and equipment be duplicated within each sensor unit, unlike the present invention which requires only a multiple of sensor units to achieve total area protection.
The main object of this invention is to provide a total system to accurately detect and warn of the presence of smoke, fire, carbon monoxide, hydrogen and hydrocarbon gases, volatiles of paints, varnishes and other household and industrial compounds containing hydrocarbons. The object has a related object to warn with a performance level equal to or greater than existing systems, and to warn without the danger of causing fire or explosion as a consequence of the alarm design itself.